Hi, If you have a USB webcam please let me know what happens if you disconnect its usb cable while it is streaming images to a v4l viewer (e.g. xawtv) I'm trying to understand what the "normal" behaviour of a USB v4l1 webcam should be (and what it actually is) when the usb cable is just yanked out and the /dev/video<n> it is connected to disappears. (even if the cable is not yanked, 2.4.x usb/hub.c can simulate this if the USB hub bandwidth is overloaded, which it seems to intepret as "Electromagnetic Interference (EMI) due to bad cables", according to an error message.... ) I'm working on maintaining the cpia driver, and this causes a nasty hang of the v4l application (xawtv, gqcam...) when one tries to close the app, the app (and the kernel driver) are left in a frozen "busy" state that can only be cleared by a reboot.... The same thing happens when I yank the usb cable of a running ov511 cam, so its not just a cpia issue.... (I only have cpia and ov511 cams to test with). Do *any* usb v4l1 webcams + apps behave nicely when the cable is yanked? (I would like to hear about actual behavior, not just theoretical!) I would guess what *should* happen is that image on the v4l app freezes (I see this), but the app should be closable and the kernel module unloadable before the app is closed. In my case, I see that deregistration of the cpia module is postponed until I attempt to close the app, (which until then shows a frozen image, and is producing lots of error messages that the image can't be found) and then the hang occurs. The XFree86 desktop still functions OK, but it hangs if I attempt to log out. (because the v4l app cant be shut down). Thanks for any info about how other drivers/apps handle this. ---------------------------------- E-Mail: Duncan Haldane <f.duncan.m.haldane@xxxxxxxxxxxxxxxx> Date: 02-Dec-2002 Time: 12:20:09 This message was sent by XFMail ----------------------------------
